External fixation apparatus

ABSTRACT

The external apparatus for fixing bone fragments consists of a tube-shaped portion, of which the internal space is filled with glass fibre. The fixing tube is secured by means of nails or screws (12) to the bone fragments to be fixed, whereby a rapid hardening material is introduced into the closed tube system after completion of assembly. After setting, a plastic-glass fibre composite is obtained which has excellent strength properties and is ideally suited for use as an external fixation apparatus.

The present invention relates to an external fixation apparatuscomprising at least one flexible tube-shaped portion which is disposedexternally of the patient opposite the bone fragments to be fixed andwhich is connected with the wires, nails or screws secured in thevarious bone fragments, wherein the tube-shaped portion filled with ahardenable material, after the material is hardened, forms a rigid framewith the wires, nails or screws which holds the bone fragments togetherin a desired position for the union of the same.

External fixation apparatuses serve for the orthopedic fixation and theholding together of bone fragments. Fractured bones are fixed in theirposition relative to one another with an external fixation apparatus sothat the healing can take place in the correct position. For thispurpose, bone nails, preferably with a thread, e.g. Schanz's screws orbridging rods, are inserted into or through the bone and, at their endsprojecting from the body, interconnected by at least one rod-shapedmember, e.g. a sliding rod or a guide rod. This connection is broughtabout with the aid of tightening means that are constructed as shims,articulation pieces and, if necessary, as ball-and-socket joints, ascoupling means or as grips or the like. A frame structure can thus beformed, with the aid of which the bone fragments can be rigidly fixedand held.

Known tightening means consist of non-oxidizing steel. When the fixationapparatus is applied and the rods are tightened, the entire framestructure is relatively loose, wobbly and displaceable into itself sincethe rods to be reciprocally held have to be slackened in the tighteningmeans so that they can be brought into the correct position. Hence theapplication of a fixation apparatus can, in the end, not be carried outby a single person, but additional assistants are needed for holding thejoints and double joints as well as the frame until, subsequent to thepositioning, the tightening and fixing can ultimately be carried out. Inorder to facilitate this work, separate tightening devices may beemployed. However, since steel has a very high elasticity coefficientand a smooth surface, it is not possible to obtain only a weak clampingby tightening a clamping bolt; on account of the high elasticitycoefficient, already a slight turning of a setscrew brings about a verysubstantial change in the gripping pressure. Consequently, when fittingthe fixation apparatus, the rods, bones nails or screws can only lieloosely within the tightening means. Added hereto is the circumstancethat the components and elements used for the fixation apparatus, due totheir material selection, impair X-rays. Moreover, the production costsof fixation apparatuses constructed in this fashion are very high.

The utlization of metal components predominates from which the fixationapparatus is assembled by the surgeon depending on individualrequirements. In order to obtain a radiotransparency with fixationapparatuses, use is also made of components fabricated from non-metallicmaterials. Thus, from the DE-A-27 45 504, a device for theimmobilization and/or support of human or animal limbs is known whichpossesses connecting members that are oppositely located in pairs andaccommodate at least one bone screw or one bone nail each, which, viaclamping members, are connected by means of connecting rods or threadedrods. The connecting members, the clamping members and the connectingrods as well as the integrated tighteners consist in this case of fiberreinforced thermoplastics.

Furthermore, from the DE-A-31 41 909, an orthopedic fracture fixationdevice with at least one elongate part located externally of the patientis known, which is connected by means of fracture pins or the like thatcan be secured in the various fragments of the broken bone, wherein theelongate part and the pins form a rigid frame holding the fragments inthe desired position for their union. The elongate part locatedexternally of the patient, which is secured to the various fragments ofthe fractured bone by means of bone pins, comprises an elongate carrierof flexible shape which is filled with a hardenable material which isdisposed inside the carrier in an inactive free-flowing state.

Fixation apparatuses in which preformed and rigid components areemployed are very expensive in the production of the kit required ineach particular case. A specific kit only possesses an applicabilitywhich is restricted to specific fractures, a circumstance which entailsthe maintenance of stocks and the storage of a comprehensive assortmenntof the individual components. After repeated use threaded componentsshow signs of wear. If metallic materials are used, the radiographicchecking of the healing of the fracture is possibly significantlyimpaired. With each patient who has been fitted with a fixation device,a part of the kit in stock is blocked for weeks, which necessitates afurther extension of a maintenance of stocks of the individualcomponents. The unreliable patient and the patient who passes throughfails to return to the hospital which has been the prime supplier. Thefitted components do not return into the possession of the hospital,whereby a substantial loss of components comes about. In addition, therigid kit systems force to a varying extent an arrangement of fracturefragments as well as of the external fixation device which is inconformity with the coordinates. In order to arrive at a good operationresult under these constrains, not infrequently a great deal ofexperience as well as both spatial and planning imagination are calledfor.

In the case of external fixation devices consisting of flexiblecomponents which, by thermosetting or hardening, are transformed into arigid system, use is made of a hose filled with liquid plastic which,however, can only after the fixation of the nails on the bone, be pushedover the free ends of the same. For, in a reversed sequence, the pointsof the nail would, since such a hose is not sterilizable, both spread aninfection as well as transport monomeric plastic into the organism. Dueto this prior condition, a parallel arrangement of the nails isnecessary, which comes close to the constraints imposed upon the surgeonby the rigid system. A fixation in more than one plane, which is at alltimes to be strived for on account of mechanical considerations, cannotbe managed with a hose. To a varying degree all homogeneous plasticmaterials possess only a minor breaking strength with, at the same time,a low elasticity. From this results the necessity of large crosssections of the supporting fixation device hose, without any guaranteethat the fixation device will not break after all at some time or otherdue to a peak load. Added hereto is the circumstance that a thoroughblending or mixing of the plastic components in an already filled hoseentails several disadvantages. The risk of an incomplete mixing with theconsequence that soft and more easily deflectable hose sections areobtained after the termination of the operation is relatively great.Over and above that, an imperfect mixing increases the proportion ofremaining and possibly toxic monomers in the fixation device. An as goodas possible thorough blending is possible only in a soft supporting hosewhich can readily be pressed in. This has as a consequence that an asconstant as possible cross section of the plastic cannot be ensured,especially not if the fixation device hose is installed in numerousspirals. The thorough mixing of the components of which the hardenablematerial consists when using a hose which is already filled does, to allintents and purposes, invariably lead to an escape of plastic materialfrom the points punctured by the nail and, thereby, to an incalculableloss of substance and stability. When hardening or curing by supplyingheat or radiation, the following additional problems arise: Only surfacecoatings can be polymerized by means of radiation. A completely filledhose is hardly polymerizable by radiation. Infrared radiation isintended to penetrate hose systems located close to the skin level--2 to5 cm--but not to warm the skin itself. It is true that to protect apatient against ultraviolet radiation is simpler than against infraredradiation, however, with both types of radiation an extensiveillumination of the hose system must be achieved. This has to take placesimultaneously with a fluoroscopy and the resetting maneuver by thesurgeon, an overall arrangement which is possibly difficult to put intoeffect from a technical point of view. In the case of a photosensitiveplastic which is protected by a light-proof sheet, the piercing of thehose by fixing nails may already trigger off the hardening process. Afinal bone resetting is held in position by the surgeon forapproximately 5 minutes. The fixation device must have hardened withinthis period. Longer hardening or curing times increase the exposure toX-rays and harbour the risk of a more likely worse resetting result dueto the surgeon tiring.

The present invention solves the technical problem of providing anexternal fixation apparatus of the aforementioned type, with which asimple manipulation without any imposed levels of work with thepossibility of effecting positional corrections of the fixation hose ortube prior to the hardening of the filler material without anydisplacements of straightened bone fragments occurring so that alsocomplicated bone fractures, i.e. a large number of bone fragments, canbe maintained in the correct position until the filling material is set,whereby a universal applicability is ensured and a limited maintenanceof stocks with a small assortment of the fixation apparatus componentsis possible. In addition, it is intended that a radiotransparency aswell as a great stability and high elasticity exists already in the caseof small cross sections. It is furthermore the object of the inventionto provide a tube-shaped portion for an external fixation apparatuswhich may at the same time be used as a mold for the plastic to be curedand the hose body of which forms an intimate bond with the set plastic.

This technical problem is solved by the features characterized in claim1.

By the use of a tube-shaped portion in an external fixation apparatuscomprising a plastic hose with an inserted glass fiber hose or a glassfiber reinforced plastic or of a glass fiber fabric embedded in aplastic, all the shortcomings to which the known external fixationdevices are subject, are remedied. A tube-shaped portion constructed insuch a way is filled with quick-curing synthetic resin subsequent to theassembly having been carried out so that, from a flexible, easilyhandled material, a rigid external fixation apparatus is obtained which,moreover, is radiotransparent, is very inexpensive and, when employingvarious hose thicknesses and glass fiber fillings, can be universallyemployed so that every required strength is obtained. Using the externalfixation apparatus as a disposable article circumvents the problem ofwear and tear. The use of a plastic-glass fiber composite in an externalfixation appartus means that for the first time a material is employedthat enables the operating surgeon for the first time to have at hisdisposal a system for the orthopedic fixation as well as for holding thebone fragments together with which the requirements stipulated for anexternal fixation apparatus are met. Particularly by the use of a glassfiber filled spiral hose, a fixation apparatus hose is obtained which,during the assembly of the fixation apparatus, allows itself to bereadily deformed and bent aside in different planes without anycross-sectional changes occurring at the bending points, which, on theone hand, is to be ascribed to the specific inherent stability of thefixation apparatus hose and, on the other hand, to the circumstance thata glass fiber fabric hose is inserted into the plastic hose.

When shaping and fitting the fixation apparatus hose into position, itis precisely this deformation resistance which ensures an unimpededpassage of the introduced free-flowing plastic material which, followingthe thorough mixing of the components outside the hose, is injected intothe same. Within the fixation apparatus hose a "thorough blending" ofwoven glass fibers with the synthetic resin then takes place and aplastic-glass fiber composite comes into existence. The glass fibersanchored in the material of the fixation apparatus hose, or the glassfiber fabric hose inserted into the hose of pure plastic increase theultimate strength of the tube-shaped portion which is preferablyconstructed as a spiral hose and which, on account of thisconfiguration, can be bent aside without difficulty and thus installed.Due to the high resistance to fracture, hoses having small crosssections may also be employed. Also, when injecting the preferablyquick-curing synthetic resin mass, an escape of this plastic materialfrom the nail perforations in the walls of the fixation apparatus hoseis not possible since the perforations formed in the walls of thefixation apparatus hose when the fixing nails or screws are introducedwithin the penetration area of the fixing nail automatically sealthemselves again, this automatic sealing being assisted by the glassfibers incorporated into the hose material, by the glass fiber fillingor by the inserted glass fiber hose which constitute a kind of sealingsafeguard, it being advantageous in this case if tube-shaped portionsare employed which consist of a very fine-meshed glass fiber fabricembedded in a plastic or of a ver fine-meshed glass fiber fabric hose.On account of this a very thin-walled hose may also be used.

According to a further embodiment of the invention the external fixationapparatus consists of a single tube-shaped portion fabricated from aglass fiber hose inserted into a plastic hose or from a glass fiberreinforced plastic or from a glass fiber fabric embedded in a plastic,this tube-shaped portion being routed in various planes and directionsacross the bone fragments and connected with the bone fragments with theaid of the wires, nails or screws. The two free ends of this tube-shapedportion are interconnected via a preferably Y-shaped or T-shapedconnecting union which is provided with a sealable filling aperture forthe hardenable material. It is possible in this manner to fix fragmentsof fractured bones, e.g. of phalanxes, with a single tube-shaped portionwhile making use of wires, nails or screws without it being necessary toemploy an expensive frame for this. Subsequent to the quick-curingsynthetic resin having been introduced into the tube-shaped portion andfollowing the curing of the synthetic resin, a firm system which isrigid in itself is obtained so that a favorable healing process isachieved.

Furthermore, the possibility exists of joining several tube-shapedportions together so as to form a frame, all the tube-shaped portionsbeing interconnected via tubular connecting unions in such a way thatthe inner spaces of all the tube-shaped portions intercommunicate, thehose system thus constructed having at least one sealable fillingaperture provided for the hardenable material. Over and above that therealso exists the possibility of combining several tube-shaped portions ofthe hose system into groups, the hose system formed by each group beingprovided with at least one sealable filling aperture for the hardenablematerial.

It is possible in this manner to optimally adapt such an externalfixation apparatus to the various requirements while use is made ofdifferent types of connecting unions. In this case, connecting unionsbent aside at 90° or at 180°, as well as T-shaped, Y-shaped andcross-type connecting unions are employed as two-dimensional connectingpieces. In hose sections which span the fractures, preferably noconnecting unions should be incorporated since these might possibly turninto weak points of the stability.

In order to ensure an adequate transfer of force from the hose system tothe fixing nails or screws, in the case of larger nail or screw crosssections and, at the same time, of a greater rise in forces as, forinstance, infractures of the lower extremity, it no longer suffices tosimply drill nails or screws through the hose, especially as a bendingaside and embedding is no longer possible due to the larger nail crosssection. Rather, the nail or the screw will have to be anchored on thehose system with the aid of a fixation means, such a fixation meanshaving to meet the following requirements:

It must be possible to mount it at any point whatever of the hose;

It must be capable of holding the nail or screw in a rotationally stablemanner;

It has itself to be firmly secured in the glass fiber plastic of thehose in order to distribute the frictional connection;

It has to be universally employable to the highest degree for differentnail or screw cross sections;

The fixation means must be radiotransparent.

All these prior conditions are met by a fixation member comprising twoshell-shaped parts encasing the tube-shaped portions which complementone another so as to form a tubular structural element, wherein eachshell-shaped part has, on at least two oppositely located sides,shell-like-configured sections which complement one another so as toform two mutually aligned attachment studs and serve to receive a screwor a nail, the shell-shaped sections, on their outer wall, beingprovided with an external thread for accommodating a coupling nut whichoverlaps a compression ring. Apart from screws provided with a threadextending over the full length of the screw shank, it is also possibleto use screws provided with a thread on the drilled-in section while theremaining shank is constructed in a plain fashion. Even when the threadis constructed so as to be continuous on the screw shank, these screwsare handled as if no thread exists. The fitting of the shell-likeconfigured parts of the fixation member which acts like a grippingdevice is carried out subsequent to the nails or screws having beendrilled in.

According to a further embodiment of the invention, the fixation memberconsists of a tube provided with an external thread passed through twooppositely located and mutually aligned perforations in the wall of thetube-shaped portion which, within its inner space, accommodates a nailor a screw, the threaded tube being made to project on both sides with asection from the tube-shaped portion and, on its sections within thearea of its extremities, carries one coupling nut each which engageswith the external thread of the threaded tube which overlaps acompression ring that can be brought into abutment when tightening thecoupling nut fitted to the end of each section of the threaded tubeprovided on the outer wall surface of the nail or screw arranged withinthe threaded tube, wherein the threaded tube, on its section facing thebone fragments, carries a threaded coupling clamp seated upon theexternal fixation apparatus with a stud, spike or the like engaging intothe wall of the tube-shaped portion and, on its other section, anunthreaded coupling clamp with a stud, spike or the like engaging intothe wall of the tube-shaped portion, the unthreaded coupling clamp onthe threaded tube being retained by means of a nut.

These two differently constructed fixation members are adapted to thedifferent nail and screw cross sections by the employment of appropriatecompression rings and thus meet the requirements stipulated for thefixation member.

Advantageous embodiments of the invention are characterized in thesubclaims.

In the following the subject matter of the invention is explained in thedrawings.

FIG. 1 shows, in a diagrammatical view, an external fixation apparatusconsisting of several interconnected tube-shaped portions applied to twobone fragments;

FIG. 2 shows, in a diagrammatical view, an external fixation apparatusconsisting of a tube-shaped portion interconnected at the ends andsecured to two bone fragments by means of Kirschner wires;

FIG. 3 shows, partly in a view and partly in a vertical section, aKirschner wire secured to a section of a tube-shaped portion of theexternal fixation apparatus;

FIG. 4 shows a diagrammatical view of a fixation member;

FIG. 5 shows a partial cross section through the fixation member of FIG.4;

FIG. 6 shows, partly in a view and partly in a vertical section, afurther embodiment of the fixation member;

FIG. 7 shows a horizontal section according to Line VII--VII of FIG. 6;

FIG. 8 shows a longitudinal section through a perforator for insertingthe threaded tube into the fixation member according to FIG. 6;

FIG. 9 shows a diagrammatical view of a tightening means;

FIG. 10 shows a top view of the tightening means in the direction of itslongitudinal axis;

FIG. 11 shows a longitudinal section through a half of the tighteningmeans according to FIG. 9;

FIG. 12 shows, in an enlarged vertical section, a section of atube-shaped portion of a hose body fabricated from a plastic with aglass fiber fabric hose inserted into the hose body;

FIG. 13 shows, in an enlarged vertical section, a section of atube-shaped portion of a hose body fabricated from a plastic withseveral glass fiber fabric hoses inserted in a layer-like manner;

FIG. 14 shows, in an enlarged vertical section, a section of atube-shaped portion of a hose body fabricated from a plastic with aglass fiber fabric hose inserted into the hose body, with cured plasticdisposed within the inner space of the tube-shaped portion;

FIG. 15 shows, in an enlarged vertical section, a section of atube-shaped portion of a spiral hose body filled with a glass fiberfabric;

FIG. 16 shows a vertical section according to Line XVI--XVI in FIG. 15;

FIG. 17 shows, in an enlarged section, a section of a tube-shapedportion of a hose body fabricated from a plastic with glass fibersembedded in the same, and

FIG. 18 shows, in an enlarged vertical section, a section of atube-shaped portion of a hose body fabricated from a plastic with aglass fiber fabric incorporated into the same.

The external fixation apparatus shown in FIGS. 1 and 2 is identified by10. This external fixation apparatus 10 consists of a tube-shapedportion 11 or 211 in the form of a hose system 20 of several individualinterconnected hose sections, the two ends of which intercommunicate(FIG. 2). This tube-shaped portion 11 or 211 constitutes the fixationapparatus hose; its wall is identified by 111a or 211a. The securing ofthe tube-shaped portion 111 or 211 to two bone fragments identified byK1 and K2 is effected with the aid of wires, nails or screws 12.

The tube-shaped portion 211 consists of a hose body 212 fabricated froma flexible plastic which possesses a certain elasticity. This hose body212 is filled with glass fibers or other mineral fibers. This fillingwith glass fibers is carried out in the form of a hose or stocking 215fabricated from a glass fiber fabric (FIG. 12) inserted into the innerspace of the hose body 212. According to FIG. 13, it is also possiblefor several individual glass fiber fabric hoses 215,216,217 to beinserted into the inner space of the hose body 212, so that, when viewedin a cross section, several layers of glass fiber fabric result.According to a further embodiment per FIGS. 15 and 16, so many glassfiber fabric hoses are inserted into the inner space of the hose body212 that the inner space of the hose body 212 is filled completely withglass fibers. Moreover, the possibility also exists of employing a glassfiber fabric mat in lieu of the glass fiber fabric hoses that isinserted in a folded or rolled-up state into the inner space of the hosebody 212. When several glass fiber fabric hoses are used, all hoses mayhave an identical thickness; it is also possible, however, to make useof varying thicknesses.

According to a further embodiment per FIGS. 17 and 18, the tube-shapedportion 11 consists of a glass fiber reinforced plastic or of a glassfiber fabric embedded in a plastic material. According to this thetube-shaped portion 11 comprises a hose body 115 fabricated from aflexible plastic material possessing a certain elasticity into whichglass fibers 116 are incorporated for the purpose of reinforcement, itbeing of advantage in this case for glass fibers to protrude from theinner wall surface 115a or at least for said fibers to be located in thesurface of the inner wall 115a so as to, as a kind of adhesive agent, beable to form together with the plastic material cured within the hosebody 115, an intimate and compact composite.

There also exists the possibility of incorporating a glass fiber fabric118 into the plastic material in lieu of the glass fibers incorporatedinto the plastic material of the hose body 115; in this embodiment, too,the glass fiber fabric or an incorporated glass fiber mat should belocated in the surface of the inner wall of the hose body 115 (FIG. 18).Besides glass fibers, mineral fibers or filaments may be incorporatedinto the plastic material of the tube-shaped portion 11, by which allfibers are understood which are produced from inorganic materials.However, especially advantageous is here the employment of glass fibersand filaments which may also be incorporated in the form of fabrics ormats into the plastic material of the tube-shaped portion 11 or bepresent in the form of a glass fiber fabric hose inserted into theplastic hose body. Of particular advantage is the use of glass fiberreinforced thermoplastics which are provided with short glass fibresthat are less than 1 mm in length or with glass fibers of up to 3 mm inlength, it being possible, however, to also employ glass fibers of agreater length in this case. ABS, polyamides, PC, PE, POM, PP, PS, PVC,SAN, PETP and PBTP may be employed as glass fiber reinforcedthermoplastics; essentially those materials or thermoplastic findingemployment here which are suitable for the production of the tube-shapedportion 11 for the external fixation apparatus and which, in connectionwith the proximity of the skin, possess a good dermal compatibility.Fabrics manufactured from glass rovings, glass filaments, glass threadsor chopped strand mats may be used as glass fiber fabric. In this casethe glass fiber fabrics may possess the most widely varied weaves. Thus,by way of example, two-strand weaves, body weaves and Atlas weaves maybe employed; but all other types of suitable weaves may also be used forthe fabrication of the glass fiber fabric.

For producing the external fixation apparatus 10, the tube-shapedportion 11 or the tube-shaped portion 211, respectively, which is filledwith glass fibers, is filled with a hardenable material subsequent tothe application and the fixation of the bone fragments. In particularsuch plastic materials are used which are quick-curing since it isensured only by the employment of quick-curing plastic materials thatthe fixed bone fragments retain their predetermined position after thehardening. In addition, due to the short curing time, the operatingsurgeon is provided with the possibility of holding the aligned bonefragments in the aligned position without the surgeon suffering fromfatigue symptoms which might result in an arrangement of the bonefragments which is no longer in the correct position. Preferablyquick-curing material is made use of, it being possible, however, toalso employ light in this case for shortening the setting time if anappropriate hardenable material is used. The quick-curing plasticmaterial is prepared outside the fixation apparatus hose by mixing thetwo components (hardener and plastic material mass) and is then injectedinto the fixation apparatus hose. It is of advantage if the hose body212 consists of a transparent or crystal-clear plastic material and ifthe plastic material to be injected is dyed. When injecting this dyedplastic material mass, it will then be possible to observe thedistribution of the mass of plastic material within the inner space ofthe hose body and to check whether all the sections of the hose body 212are filled to capacity with plastic material mass.

Instead of the tube-shaped portion 11 used in the embodiment describedhereinafter, in the embodiment forms shown in FIGS. 17 and 18 it is alsopossible to employ tube-shaped portions 211 which possess theconstruction depicted in the FIGS. 12, 13, 15 and 16 and described inthe foregoing.

In the embodiment shown in FIG. 2, the external fixation apparatus 10consists of a tube-shaped portion 11, the two ends of which 11a,11b areunited in a connecting union 16 which is provided with a sealablefilling aperture 14. The introduction of the castable or free-flowingplastic material into the inner space of the tube-shaped portion 11 iseffected in the direction of the arrow X. The tube-shaped portion 11 isconnected with the two bone fragments K1,K2 by means of Kirschner wires,i.e. the tube-shaped portion 11 is secured to the two bone fragmentsK1,K2 with the aid of these Kirschner wires and this in such a mannerthat the tube-shaped portion 11 comes to lie a slight distance above thetwo bone fragments. If several bone fragments have to be fixed, thenthis tube-shaped portion 11 is routed at different levels and indifferent directions across the bone fragments, the securing of thetube-shaped portion 11 to the individual bone fragments then beinglikewise effected via Kirschner wires 30 or by means of other suitablewires or pins, the Kirschner wires then engage on one side of theindividual bone fragments and, with their other ends, are connected withthat section of the tube-shaped portion 11 which faces the bone fragmentto be fixed. Since the tube-shaped portion 11 in the embodiment shown inFIG. 2 is disposed only above and on one side of the bone fragments, theKirschner wires 30 are secured in the individual bone fragments on oneside only. The sections of the Kirschner wires that are passed throughthe bone fragments are in this case not connected with an appropriatetube-shaped portion 11 with their free ends, however, the possibility ofemploying two tube-shaped portions 11 exists here as well, of which theone tube-shaped portion 11 comes to lie above the bone fragments to befixed and the other tube-shaped portion 11 below the bone fragments tobe fixed, so that the two tube-shaped portions 11 are theninterconnected when the Kirschner wires 30 are at the same time passedthrough the bone fragments. The disposition of the tube-shaped portion11 above the bone fragments K1,K2 can be effected in such a way that theKirschner wires 30 are all introduced into the bone fragments in thesame direction. As shown by FIG. 2, the tube-shaped portion 11 can bedisposed in such a way that e.g. two Kirschner wires 30 are passedthrough the section 11c of the tube-shaped portion 11 in the verticaldirection, while the other section 11d of the tube-shaped portion 11 isbent aside relative to the section 11c in such a way that the Kirschnerwires 30 passed through this hose section 11c come to lie transverselyto the longitudinal direction of the Kirschner wires passed through thesection 11c of the tube-shaped portion 11c. For such an arrangement andallocation of the two sections 11c,11d of the tube-shaped portion 11,the connecting union 16 employed may then possess an appropriate shape.The tube-shaped portion 11 consists also in this embodiment of a planfiber-filled plastic material or of a glass fiber fabric embedded in aplastic material, while the tube-shaped portion 11 may also beconstructed as a spiral hose. The securing of the tube-shaped portion 11on the bone fragments K1,K2 may be carried out by means of Kirschnerwires 30, but may also be effected with the aid of differentlyconstructed wires, nails or screws.

In order to achieve a rotationally stable firm attachment of theKirschner wires 30 on the tube-shaped portion 11, the free end of eachof the Kirschner wires 30 is bent into a U-shape at approximately 180°.This bent wire end is identified by 30a (FIG. 3). The free end 30b ofthe bent wire section 30a may be constructed in a chamfered manner orextending pointedly so that any easy piercing and insertion into thewall 111 of the tube-shaped portion 11 is possible.

In the embodiment of an external fixation apparatus 10 shown in FIG. 1,a frame 20 is produced from a number of individual interconnectedtube-shaped portions 111, in which the two bone fragments K1,K2 areclamped and fixed by means of nails, screws or wires 12. This frame 20is formed by three longitudinal members 21,22,23, of which, for example,each longitudinal member consists of two interconnected sections. Thesethree longitudinal members 21,22,23 are connected via semicircularmembers 24,25 within the area of their free ends, the semicircularmembers likewise consist of two arcuately configured and interconnectedsections each. The longitudinal members 21,22,23, the semicircularmembers 24,25 and the individual sections as well from which thelongitudinal members and the semicircular members are made up, areinterconnected via ties 26, said ties 26 just as also the connectingunion 16 in the external fixation apparatus shown in FIG. 2 beingconstructed in a tubular fashion. These ties 26 are construction asT-pieces or bends. If two longitudinal member sections areinterconnected, then the tie is constructed merely tubularly. It isessential that all tube-shaped portions which are joined in order toform the frame 20 with the aid of the ties 26 be interconnected viathese ties 26 in such a way that a freely accessible inner space isprovided. For introducing the hardenable material into the inner spaceof this frame 20 constituted of the various tube-shaped portions 11, asealable filling aperture is provided which is not depicted in thedrawing. However, here too exists the possibility of providing severalfilling apertures which should then preferably communicate viaappropriate connecting tubes with a single filling device so as toensure a uniform introduction of the hardenable material in order toachieve that, especially when quick-curing plastic materials areinvolved, plastic material is introduced and contained almostsimultaneously within the inner space sections of the frame 20.

In the embodiment shown in FIG. 1, the frame 20 made up of thetube-shaped portion 11 is constructed in such a way that nails, screwsor wires 12 can be arranged extending in the vertical direction, in thiscase the pins 12 extend in the vertical direction and are retained inthe longitudinal member 23 embedded in the bone fragments alone, whilethe pins or nails 12 which are passed through the longitudinal members21,22 in one plane are passed through the bone fragments K1,K2. However,there also exists the possibility that the two bone fragments K1,K2being fixed are then surrounded on all sides by the frame 20 so that thenails, pins or screws 12 passed through the bone fragments are, in eachcase, arranged at both ends in the longitudinal members forming theframe 20.

Apart from this there also exists the possibility of combining intogroups several tube-shaped portions 11 of the frame 20, i.e. of thethusly formed hose system, in which the hose system formed by each groupis provided with at least one sealable filling aperture for thehardenable material. In all the constructed individual hose systems thefilling with hardenable material can be carried out simultaneously orsuccessively at short intervals.

The fracture gap formed between the two bone fragments K1,K2 isindicated at BS in the FIGS. 1 and 2.

In order to firmly secure the nails or screws on the hose systemconsisting of the tube-shaped portions 11, a fixation member 40 isprovided which possesses the configuration depicted in FIGS. 4 and 5.This fixation member 40 consists of two approximately semicircularlyconfigured shell-shaped parts 41,42 which complement one another so asto form a tubular structural element 43, this tubular structural element43 has a diameter which corresponds roughly to the external diameter ofthe tube-shaped portion 11. Apart from tube-shaped portions 11 having acircular cross section, is is also possible to employ tube-shapedportions possessing an oval cross section. The two shell-shaped parts41,42 of the fixation member 40 forming the tubular structural element43 are appropriately configured in the external shaping of thetube-shaped portion 11 used.

Each shell-shaped part 41 or 42 of the fixation member 40 possesses ontwo oppositely located sides molded-on and shell-like configuredsections 44,45 or 46,47, which complement one another so as to form twomutually aligned attachment stubs 48,49 and which serve to accommodate ascrew or a nail 12. The shell-shaped sections 44,45 or 46,47 areprovided on their outer wall with an external thread 50 onto which acoupling nut 51 is screwed. The mounting and attachment of a nail, pinor screw 12 is effected by employing a compression ring 55 which isembraced by the coupling nut 51 screwed onto the external thread of theattachment stub 48 or 49. The disposition of the compression ring 55 hasin this case been selected in such a way that the compression ring 55rests upon the free end of the attachment stub 48 or 49 possessing acircular cross section, so that the screwed-on coupling nut 51 overlapsthe compression ring 55. When tightening the coupling nut 51, thecompression ring is pressed together in the direction of the arrow X1with the result that it simultaneously abuts against the outer wallsurface of the nail 12, to be more precise, while a pressing effect isdeveloed so that the nail 12 is retained firmly in the fixation member40. The wall 111 of the tube-shaped portion 11 arranged within thefixation member 40 is, in the extension of the two attachment stubs48,49, provided with appropriate openings which may be constructed priorto the insertion of the nail 12. However, since the tube-shaped portionconsists of a glass fiber reinforced plastic or of a glass fiber fabricembedded within a plastic possessing a certain capability of elasticrestoration, the material of the tube-shaped portion 11 expands in sucha way that, when the nail 12 is pressed into the same, the nail 12 canbe pressed through the wall 111 of the tube-shaped portion 11 withoutdifficulty so that, in this fashion, also nails having larger diameterscan be easily secured. The attachment stubs 48,49 of the fixation member40 are, as far as their diameters are concerned, adapted to thediameters which the nails or screws used to have. Due to the compressionring 55 used on the attachment stubs 48,49 developing an adequatepressing force when the coupling nuts 51 are tightened, the possibilityalso exists of securely retaining nails and screws in the attachmentstubs 48,49 when the nails or screws 12 employed have a smaller diametercompared with the inner diameter of the attachment stubs 48,49. Theattachment stubs 48,49 are constructed in an identical manner and alsopossess identical cross-sectional surfaces and diameters.

For fixing the tube-shaped portions 11 arranged within the fixationmember 40, the shell-shaped parts 41,42 which form the tubularstructural element 43, are, on their inner wall surface, provided withfixation studs, spikes or the like 52 which are pressed into the wall111 of the tube-shaped portion 11 when the fixation member is applied.The number of these fixation studs, spikes or the like 52 can be anynumber whatever. However, it suffices if, within the area of the twoextremities of the fixation member 40, two oppositely located fixationstubs or spikes are provided (FIGS. 4 and 5).

If the fixation member 40 is used in conjunction with pins, nails orwires 12, then the inner wall surfaces of the two attachment stubs 48,49may be constructed in a plain manner. However, if screws or pins ornails with threads provided at their ends are employed, then it isadvantageous if the attachment stubs 48,49 have an internal threadprovided on their inner wall surfaces so that an additional securing ofthe screws 12 is possible. However, since the securing and mounting iseffected by means of the compression rings 55, it is not necessarythough for the attachment stubs 48,49 to be provided with a thread ontheir inner wall surfaces. Nails, screws or pins 12 can be retained in alike manner with the fixation member 40.

In a further embodiment of a fixation member 40 according to FIG. 6,this fixation member consists of a tube 141 provided with an externalthread 160 which, within its inner space, accommodates a nail or a screw12 for fixation with the bone fragments. This threaded tube 141 ispassed through the wall 111 of a tube-shaped portion 11. For thispurpose it is advantageous if two mutually aligned perforations 113,113a are constructed in the wall 111 of the tube-shaped portion 11.

The threaded tube 141 of the fixation member 140 is then arranged withinthe tube-shaped portion 11 in such a way that the threaded tube 141projects on both sides with a section 142 or 143, respectively, fromthis tube-shaped portion 11. The external thread 160 provided on theouter wall surface of the threaded tube 141 may in this case extend overthe entire length of the tube 141. However, there also exists thepossibility of providing external threads solely within the area of thetwo extremities 142a,143a of the two threaded tube sections 142,143.

The threaded tube 141 is provided on its sections 142, 143, within thearea of their extremities 142a,143a, or on its end, respectively, withone coupling nut 144 or 145 each which engages with the external thread160 of the threaded tube 141. Each coupling nut 144 or 145 overlaps acompression ring 146 or 147 (FIG. 6) which can be brought into abutmentwhen tightening the coupling nut 144 or 145 fitted to the end of eachsection 142,143 of the threaded tube 141 provided on the outer wallsurface of the nail or screw 12 arranged within the threaded tube 141.On the threaded tube 141, at its extremities, the compression rings146,147 are then disposed with the coupling nuts 144,145 overlappingthem. When tightening the coupling nuts 144,145 in the direction of thearrows X2, X3, the compression rings 146,147 are pressed together insuch a way that they are made to abut against the nail or the screw 12.The compression rings 55 and 146,147 consist of suitable deformablematerial such a rubber or plastics which, if at all possible, does notshow any signs of indentation.

In addition, the threaded tube 141 carries a threaded coupling clamp 148on its section 143 and, on its section 142, an unthreaded coupling clamp150. The threaded coupling clamp 148 is of annular configuration and isprovided with an internal thread so that the coupling clamp 148 can bescrewed onto the external thread of the threaded tube 141. This couplingclamp 148 has at least two mutually aligned studs or spikes or the like149 which point in the direction of the tube-shaped portion 11 andengage into the wall 111 of the tube-shaped portion 11. In order to makesure that the studs, spikes or the like 149 of the coupling clamp 148engage into the wall 111 of the tube-shaped portion 11, the couplingclamp 148 is not screwed onto the external thread 160 of the threadedtube 141, but, by rotating the threaded tube 141 around its longitudinalaxis, the coupling clamp 148 is brought so close to the wall 111 of thetube-shaped portion 11 that the studs, spikes or the like 149 on thecoupling clamp 148 engage into the wall 111 of the tube-shaped portion11.

For this reason the coupling clamp 150 on the section 142 of thethreaded tube 141 is not provided with a thread, but this coupling clamp150, which is likewise of annular configuration, is moved by means of anut 152 up to the wall 111 of the tube-shaped portion 11. For thispurpose the nut 152 is screwed onto the external thread of the threadedtube 141. The coupling clamp 150 also has two mutually aligned studs,spikes or the like 151 which assume the position shown in FIG. 6 andwhich, when the coupling clamp 150 is brought up to the wall 111 of thetube-shaped portion 11, engage into the wall 111. Following this the twocoupling clamps 148,150 are retained on the threaded tube 141 in such away that their studs, spikes or the like 149,151 are located oppositeone another.

This fixation member 140 is used in such a fashion that the threadedtube 141 is passed through appropriately constructed openings in thewall of the tube-shaped portion 11. Following this, the coupling clamps148,150 are mounted and, by rotating the threaded tube 141, the threadedcoupling clamp 148 is moved up to the wall of the tube-shaped portion 11so that its studs, spikes or the like 149 engage into the wall of thetube-shaped portion 11 or are passed through the wall 111 which, onaccount of the material used for the tube-shaped portion 111, ispossible without afterwards, when the hardenable material is introducedwithin these areas, material will escape at these puncturing points oris pressed out from these puncturing points.

The unthreaded coupling clamp 150 is mounted on the threaded tube 141 inthe same fashion and, by means of the screwed-on nut 152, is moved up tothe wall 111 of the tube-shaped portion 11 so that the studs, spikes orthe like 151 of the coupling clamp 150 engage into the wall 111 of thetube-shaped portion 11 in the same way as the studs, spikes or the like149 (FIG. 6).

Furthermore, the coupling clamp 150 is provided with arotation-suppressing means, to be more precise, in the form of a cam 154constructed or formed on the inner wall surface of the coupling clamp150 which engages into a recess constructed in the outer wall surface ofthe tube-shaped portion 11 at 112 (FIG. 7). The rotation-suppressingmeans is in this case located between the coupling clamp 150 and thethreaded tube 141 so that, between the nail and the tube-shaped portions11, after the filling in and curing of the plastic mass, a rotationalstability is produced.

For the insertion of the threaded tube 141, a perforator 155 is providedwhose point is indicated at 156. This perforator is screwed in for theinsertion of the threaded tube 141.

For the positioning and fixation of bone fragments it is often necessaryto construct the external fixation apparatus in such a way that theretightening or a tightening in the first place is possible. For thispurpose a tightening means 60 is provided which consists of two tubularsections 61,62 which are closed at their extremities (FIG. 9), saidextremities being provided with external threads on their outer wallsurfaces. Of the two external threads of the two tubular sections 61,62,one external thread is constructed as a right-handed thread 63 and theother external thread as a left-handed thread 64. Each tubular section61,62 has, at its external end 61a,62a, an adapter or connecting union65 for tube-shaped portions 11. These adapters or connecting unions 65can likewise be constructed along with the tubular sections 61,62 fromthe same material as these; however, here, too, the possibility existsof employing separate adapters or connecting unions 65 which are thenconnected with the tubular sections 61,62 while use is being made ofsuitable connecting means such as e.g. screwed connections. The externaldiameter of these adapters or connecting unions 65 corresponds to theinternal diameter of the tube-shaped portions 11 to be connected.

A tubular tightening nut 66 is screwed onto the external threads of thetwo tubular sections 61,62, the outer wall surface of which is providedwith a grip grooving or fluting. In the embodiment shown in FIG. 9, thetightening nut 66 is provided with a number of gripping surfaces 66awhich are obtained by a hexagonal cross-sectional construction of thetightening nut (FIG. 10). This tightening nut 66 is provided with anumber of drilled holes 67 which are arranged in series, i.e. locatedside-by-side and extend in the longitudinal direction of the tighteningnut. These drilled holes 67 serve for the observation and the checkingof the tightening path, hence these drilled holes 67 have the functionof observation windows. Sections of the outer wall surface of the twotubular sections 61,62 of the tightening means 60 are preferablyprovided with a different color scheme so that then, with the aid of thecolors which can be seen through the drilled holes 67, an evaluation ofthe tightening path can be made. In order to achieve a secure seating ofthe tube-shaped portion 11 on the adapter or connecting union 65, theseare, on their outer wall surface, provided with a corrugated or ribbedfinish which is indicated in FIG. 11 at 68. A ventilation aperture isidentified by 69. With a tightening means 60 constructed in this mannera structural element is provided with which a tightening of thetube-shaped portions, e.g. within the frame 20, can be easily effectedso that, apart from a tightening, the tightening means at the same timepossesses bridging and additional securing properties. The tubularsections 61,62 may also be constructed as hollow screws or banjo bolts,the inner spaces of which are filled with glass fibers, which iseffected by a cutting back of the plastic hose body 212 accommodatingthe filling of glass fiber so that a section of the pure glass fiberfilling or of the glass fiber fabric hose is obtained. This section ofthe glass fiber filling or of the glass fiber fabric hose serves to fillthe hollow screw and thus leads to a rigid bond between the tighteningmeans 60 and the fixation apparatus hose after the filling withsynthetic resin which, when poured out, flows into the exposed sectionof the glass fiber filling located within the inner space of the hollowscrew. The construction of the tightening means 60 as a hexagon has atthe same time the advantage that, with the aid of appropriatelyconstructed tools, it is possible for the tightening means 60 to beseized on the outside and to be turned around its longitudinal axis fortightening.

As fixation apparatus hoses, i.e. as tube-shaped portions 11, it is alsopossible to employ plastic hoses which, externally or internally, areprovided with a glass fiber fabric, these glass fiber fabrics beingembedded within the plastic during the manufacture of the hose materialfrom plastic.

When using Kirschner wires 30 it is also of advantage to secure thesewires 30 by means of cable ties 80 laid around the fixation apparatushose and the wires 30 (FIG. 3). The cable ties prevent a sliding out ofthe wires 30 from their anchoring in the fixation apparatus hose priorto and during the filling of the fixation apparatus hose with syntheticresin.

The fixation member 40,140 and the tightening means 60 consist ofsuitable plastics of great strength, especially breaking strength; it ispossible, however, for other suitable material to be used.

According to FIGS. 12 and 13, the tube-shaped portion 211 consists of ahose body 212 that is fabricated from a flexible plastic. A hose 215fabricated from glass fiber fabric is inserted into the inner space ofthe hose body 212 which rests against the inner wall of the hose body212. If use is made of a hose system consisting of several tube-shapedportions 211, then the glass fiber fabric hoses are inserted into theindividual hose sections prior to the hose sections being joinedtogether and interconnected. It is also possible to use longerdimensioned hose bodies 212 with inserted glass fiber fabric hose 215that are cut to the required lengths for use.

A glass fiber fabric 215 may be inserted into the inner space of thehose body 212 (FIG. 12), but several glass fiber fabric hoses215,216,217 may also be inserted thus forming several layers (FIG. 13).Depending on the requirements, the glass fiber fabric hoses may havedifferent wall thicknesses. A thusly constructed tube-shaped portion 211is then filled with the hardenable plastic. In FIG. 4, the cured plasticis indicated at 90. The advantage consists in that such a fixationapparatus hose can be sterilized prior to use. Also the glass fiberfabric hose can be sterilized prior to its insertion into the hose body.The tube-shaped portion 211 thus has the function of a mold. After theeffected introduction into the hose system, the hardenable plasticpenetrates into the glass fiber fabric of the glass fiber fabric hoseand flows through the glass fibers so that, following the curing, arigid intimate bond between the glass fiber fabric and the plastic isproduced. The external hose body fabricated from plastic merely has aholding-together function and serves to effect the external delimitationand may, therefore, be constructed with thin walls. In this way acomposite of great stability is obtained. This stability is adjustableby employing a varying number of glass fiber fabric hose layers.

According to the FIGS. 15 and 16, the hose body 212 is of spiralconfiguration and consists preferably of a transparent or crystal-clearplastic. The inner space of the hose body 212 is provided with a glassfiber filling 218 which consists of a rolled-up glass fiber fabric mator of several glass fiber fabric hoses inserted into one another. Thisglass fiber filling 218 fills the inner space of the hose body 212.

I claim:
 1. An external bone fixation apparatus, comprising at least oneflexible tube-shaped portion which is externally arrangeable on apatient, opposite bone fragments to be fixed; and connecting meanssecurable in the bone fragments for connecting with the at least oneflexible tube-shaped portion, the tube-shaped portion being filled witha hardenable material which, subsequent to hardening thereof, forms arigid frame with the connecting means so as to hold the bond fragmentsin a desired position to enable healing thereof, the tube-shaped portionbeing formed of a glass fiber-reinforced material, and one oftransparent and clear plastic in the shape of a spiral tube having abead-like reinforcement which is arranged in a closed tube system, thehardenable material being a quick-curing plastic which is filled intothe interior of the closed tube system.
 2. An external bond fixationapparatus, comprising at least one flexible tube-shaped portion which isexternally arrangeable on a patient, opposite bone fragements to befixed; and connecting means securable in the bone fragments forconnecting with the at least one flexible tube-shaped portion, thetube-shaped portion being filled with a hardenable material which,subsequent to hardening thereof, forms a rigid frame with the connectingmeans so as to hold the bone fragments in a desired position to enablehealing thereof, wherein the tube-shaped portion is formed of a tubebody of one of a transparent and a clear plastic filled with glassfibers so as to form a spiral tube having a bead-like reinforcementarranged in a closed tube system, the hardenable material being aquick-curing plastic filled into the interior of the closed tube system.3. An external bond fixation apparatus, comprising:at least one flexibletube-shaped portion which is externally arrangeable on a patient,opposite bone fragments to be fixed; and connecting means securable inthe bone fragments for connecting with the at least one flexibletube-shaped portion, the tube-shaped portion being filled with ahardenable material which, subsequent to hardening thereof, forms arigid frame with the connecting means so as to hold the bone fragmentsin a desired position to enable healing thereof, wherein the tube-shapedportion is formed of a glass fiber fabric embedded in one of atransparent and a clear plastic and is formed as a spiral tube having abead-like reinforcement which is arranged in a closed tube system, thehardenable material being a quick-curing plastic filled into theinterior of the closed tube system.
 4. An external fixation apparatusaccording to claim 2, wherein the glass fiber filling of the tube bodyconsists of one of at least one hose inserted into the tube body and aglass fiber mat rolled so as to form a tube.
 5. An external fixationapparatus according to claim 1, and further comprising a connectingunion having a sealable filling aperture, the connecting union beingprovided so as to interconnect the ends of the tube-shaped portion. 6.An external fixation apparatus according to claim 5, wherein theconnecting union has one of a Y-shape and a T-shape.
 7. An externalfixation apparatus according to claim 5, wherein several tube-shapedportions are joined together so as to form a frame, additionalconnecting unions being provided so as to interconnect the tube-shapedportions so that the interior of all the tube-shaped portionsintercommunicate.
 8. An external fixation apparatus according to claim7, wherein the several tube-shaped portions are combined into groups,each group of tube-shaped portions being provided with at least onesealable filling aperture for the hardenable material.
 9. An externalfixation apparatus according to claim 1, wherein the connecting means isprovided so as to route the tube-shaped portion in various planes anddirections across the bone fragments.
 10. An external fixation apparatusaccording to claim 1, wherein the connecting means includes wires, eachof the wires having an end which is bent aside approximately 180°, andis thrustable into the tube-shaped portion and connectable thereto in arotationally stable manner.
 11. An external fixation apparatus accordingto claim 10, wherein the fixation wires are Kirschner wires, and furthercomprising cable ties for retaining the Kirschner wires on thetube-shaped portion.
 12. An external fixation apparatus according toclaim 1, wherein the connecting means includes a fixation member and oneof screws and nails, the fixation member being arranged so as to securethe screws and nails to the tube-shaped portion.
 13. An externalfixation apparatus according to claim 12, wherein the fixation member isformed of a tube provided with an external thread and passed through toopposing and mutually aligned perforations in the wall of thetube-shaped portion, the tube of the fixation member having an innerspace which accommodates one of the nail and screw, the threaded tubebeing provided so as to have a section which projects on both sides fromthe tube-shaped portion, a coupling nut being provided on a each ofthese projecting sections so as to engage with the external thread ofthe threaded tube, the coupling nuts each overlapping a compression ringprovided on the outer wall surface of the nail and screw arranged withinthe threaded tube, the compression ring being brought into abutment withtightening of the coupling nut fitted to each end of the projectingsections of the threaded tube, a threaded coupling clamp being providedon a section of the threaded tube facing the bone fragments, thethreaded coupling clamp being seated on the external thread with a studor spike engaging into the wall of the tube-shaped portion, anunthreaded coupling clamp with a stud or spike being provided on anothersection of the threaded tube so that the stud or spike engages into thewall of the tube-shaped portion, a nut being provided so as to retainthe unthreaded coupling clamp on the threaded tube, and a cam beingarranged so as to connect the unthreaded coupling clamp with thethreaded tube in a rotationally stable manner.
 14. An external fixationapparatus according to claim 12, wherein the fixation member is made upof two shell-shaped parts arranged so as to encase the tube-shapedportion and compliment one another so as to form a tubular structuralelement, each shell-shaped part having on at least two oppositelylocated sides shell-like configured sections which compliment oneanother so as to form two mutually aligned attachments stubs which serveto receive one of the screw and nail, the shell-shaped sections beingprovided on their outer wall with an external thread, a compression ringbeing fitted onto the end of the attachment stub and a coupling nutbeing provided on the external thread of the shell-shaped sections so asto overlap the compression ring.
 15. An external fixation apparatusaccording to claim 14, wherein each of the shell-shaped parts has aninner wall provided with at least two studs or spikes.
 16. An externalfixation apparatus according to claim 1, and further comprisingtightening means provided for each tube portion which spans a fracture.17. An external fixation apparatus according to claim 16, wherein thetightening means includes two tubular sections provided with externalthreads on their outer wall surfaces, one of the external threads beinga right-handed thread and the other external thread being a left-handedthread, each of the tubular sections have an external end on which aconnecting union is provided for the tube-shaped portions, a tubulartightening nut is provided so as to be screwed onto the external threadsof the two tubular sections and has one of a grip grooving and flutingfinish, as well as a number of poles arranged therein in a side-by-sidemanner.
 18. An external fixation apparatus according to claim 17,wherein the two tubular sections of the tightening means have an outerwall with sections of different colors.
 19. An external fixationapparatus according to claim 17, wherein ventilation apertures areprovided in the wall of the tubular sections of the tightening means.20. An external fixation apparatus according to claim 1, wherein theconnecting means includes at least one of wires, nails and pins, thewires having bent-aside ends thrust into the wall of the tube-shapedportion, the connecting means further including cable ties arranged soas to secure the bent-aside wire ends to the tube-shaped portion.
 21. Anexternal fashion apparatus according to claim 1, wherein at least onehose fabricated of a glass fiber fabric is inserted into the tube bodyof the tube-shaped portion so that the tube body with the at least oneglass fiber fabric hose and the hardenable material cured within theinterior of the tube-shaped portion form a composite.
 22. An externalfixation apparatus according to claim 21, wherein the glass fiber hoseshave identical thicknesses.
 23. An external fixation apparatus accordingto claim 21, wherein the glass fiber hoses have varying thicknesses. 24.An external fixation apparatus according to claim 21, wherein the atleast one hose includes several glass fiber fabric hoses inserted intoone another.
 25. An external fixation apparatus according to claim 21,wherein the at least one hose is a glass fiber fabric mat rolled up soas to form a hose.
 26. An external fixation apparatus according to claim1, wherein the hardenable material is provided with a color.